The thermal stability of vitamin B6 and pantothenic acid has been selected for study because several research reports indicate that these two nutrients may be particularly susceptible to thermal destruction and marginal in supply in many segments of the American diet. Activation energy and reference reaction rate constant for both nutrients will be determined as a function of the microenvironment of the food. In addition studies on the optimization of thermal processes for retention of nutrients using the Lethality-Fourier number method will continue.